Hello all.
We tried follow me mod 3.5~4 minutes without a problem but at the end our 450 quad crashed suddenly.
Motors are Sunnysky x3108s, controller Radiolink Pixhawk 1, esc are Racerstar 30A, battery 13000mah 25C 4S.
Log file is attached.
Can you please figure out why this crash happened?
Thank you very much.
Have you done a mission flight with the untune drone? Most parameters are default initialized values for a 10" propeller drone.
PSC_ACCZ_I and PSC_ACCZ_P are not set correctly for your drone.
Hi @Jai.GAY.
Thank you very much for your answer.
We use 1047 propellers. I tried autotune but i had an error “AutoTune: failing to level, manual tune may be req”.
We didnt see any oscillations so we have done mission flights and then follow me mode.
I also set PSC_ACCZ_I and PSC_ACCZ_P values but after that we changed the battery with another different weighted battery so those malues may needed to set again.
Thank you. I didn’t understand how to calibrate notch filters.
Here is a video of crash.
Your copter is untuned. You demanded more of the default control gains than it could handle, and it crashed. Not much of a surprise, and video almost never helps narrow the root cause.
Start here and go through every configuration step:
Thanks for tuning reccommendations but can anyone help with the reason for sudden crash?
I think fine tuning is necessary but first i have to fly drone first. In first 3.5 minutes quad didn’t make any oscillations or disturbing vibrations. Here is a screenshot of bat volt graph from log file. Battery voltage dropped 13.8V suddenly. What could be the reason for this?
You flew your batteries down to 3.5 volts per cell, and they could no longer sustain power output.
The rapid discharge indicates either a poorly sized battery for the application or potentially a damaged battery.
Haven’t reviewed the log, but I’m guessing you have no battery failsafe enabled and have not double checked the battery monitor calibration.
Good article on LiPo discharge recommendations:
your quad is really badly tuned its barely flying but I think the cause of the crash was motor or ESC failure. The quad tips forward and to the right, that would be consistent with motor 1 failing. the log also shows motor 1 going to maximum as it starts to fall.
You motor outputs are not uniform, have you calibrated your ESCs? or are the arms twisted?
@Yuri_Rage
Battery was a brandnew 13000mah 25C 1Kg battery.
I calibrated 3DR power module analog readings by measuring battery voltage and i activated battery failsafe.
You can see from the screenshot battery was at 15.00 Volts and suddenly dipped to 13.8 volts.
And this screenshot shows vibes.
That could also indicate a short in the ESC or motor, supporting @geofrancis analysis of motor failure. But the slope of that line is pretty steep even before failure.
Vibes are ok but could be improved. Check prop balance and secure all loose wiring.
@geofrancis
Thank you very much for reply.
Yes I calibrated ESCs. I will change ESC’s and motors and will try again.
I cant finish autotune because “AutoTune: failing to level, manual tune may be req” message.
does the frame have round arms? check they are not twisted,
check the propeller is mounted securely,
check there are no screws going into the motor wires,
check the screws going into the motor arent too long and damaging the windings.
Also, after the accident, I reassembled the drone and the motors and escs were working. But the escs and motors are old, so I think I will have to install new ones and try them.
The frame is f450.
I checked the screws touching the motor windings. I checked the cable connections. I also checked whether the propellers were connected correctly. But one thing that caught my attention was that engines number 3 and 4 were getting hotter than the others.
There is not much else we can do, when you get new escs get BLheli32 with telemetry that way you have data for each motor.
Can you please reccomend an esc for x3108s motors?
I have been using these escs, they have full telemetry
https://www.aliexpress.com/item/4000576967026.html
So, do I need to make a special setting in esc calibration screen for pixhawk to use this esc?
